(C++) GnuplotInterface
January 10, 2018 · View on GitHub
(C++) GnuplotInterface
GnuplotInterface is a class that enables the user to easily plot values in Gnuplot. It handles both the connection to Gnuplot and performs the window management as well. It creates a text-file in which the location of the Gnuplot executable can be entered (without recompiling the program).
The tool TestGnuplotInterface tests the GnuplotInterface class.
I only got this interface to work under MacOS
The one function that this class is built around is the popen function. This is a non-standard function to open a pipe. If this function is unknown under your programming environment, try either std::popen, std::_popen, std::__popen, popen, _popen or __popen.
- View a screenshot of a graph created with Gnuplot interface. Thanks to Roger Wehage for submitting this image and allowing me to use it.
- Download the 'Gnuplot Interface' source code (zip).
Known compile errors
- _popen is not a member of std
- CLK_TCK was not declared in this scope
- Duplicate symbol Gnuplot::SetLineStyles()
Technical facts
./CppGnuplotInterface/CppGnuplotInterface.pri
INCLUDEPATH += \ ../../Classes/CppCanvas SOURCES += \ ../../Classes/CppCanvas/canvas.cpp HEADERS += \ ../../Classes/CppCanvas/canvas.h OTHER_FILES += \ ../../Classes/CppCanvas/Licence.txt
./CppGnuplotInterface/gnuplotinterface.h
// // Gnuplot - a C++ class interface with Gnuplot // V4.0 // // Created by Richel Bilderbeek on Fri Jun 10 2005. // Open source. // // Richel Bilderbeek // Website: http://www.richelbilderbeek.nl // // V4.0: 19th March 2008: Conformized code // V3.0: 23th September 2006: Implemented suggestion by Christoph Schmalz. // According to Christoph it should work under Windows now. // Made the code 100% Standard C++. // V2.0: 12th September 2005: Got program to compile under Windows environment. // Program is found NOT to run under Windows. // Somebody has an idea how to open Gnuplot.exe ??? // V1.0: 10th June 2005: first version developed on Macintosh // // // This class functions well at a Macintosh. Under Windows, the pipe to the // Gnuplot executable (either MS-DOS or Windows executable) will not open. // If you have an idea to solve this, please E-mail me. // // // Feel free to contact me when: // - YOU can get the program to run under Windows (and normally it wouldn't) // - you encounter a compile error // - you have made additional functionality // - you have outsmarted me on this interface. // #ifndef __GNUPLOT_H #define __GNUPLOT_H #include <iostream> #include <string> #include <fstream> #include <sstream> #include <vector> #include <cstdio> #include <ctime> #include <cassert> enum GnuplotStyle { styleLines, stylePoints, styleLinespoints, styleImpulses, styleDots, styleSteps, styleErrorbars, styleBoxes, styleBoxerrorbars, }; enum GnuplotTerminal { terminalX11, terminalAqua }; struct WindowData { std::vector<std::string> tempFileName; }; struct Gnuplot { Gnuplot(); ~Gnuplot(); void Execute(const std::string&) const; void AddWindow(const int nWindows = 1); void ChangeWindow(const int); void SetTerminal(const GnuplotTerminal&); void SetStyle(const GnuplotStyle&); void SetYlabel(const std::string&); void SetXlabel(const std::string&); void Plot(const std::string &, const std::string& title = "y"); void Plot(const std::vector<double>&, const std::string& title = "y"); void Plot(const std::vector<double>&, const std::vector<double>&, const std::string& title = "data"); void Plot(const std::vector<double>&, const std::vector<double>&, const std::vector<double>&, const std::string& title = "z"); void EmptyPlot(); //Helper functions void Sleep(const double) const; const std::string Itoa(const int) const; const std::string Ftoa(const double) const; const bool FileExists(const std::string& fileName) const; private: std::FILE * mGnuPipe; std::string mTerminal; std::string mStyle; std::vector<WindowData> mWindowData; int mCurrentWindowNumber; static int mTempFileNumber; void SetLineStyles(); const std::string ReadFileName() const; const std::string CreateTempFileName(); void CreateTempFile(const std::string&, const std::vector<double>&); void CreateTempFile(const std::string&, const std::vector<double>&, const std::vector<double>&); void CreateTempFile(const std::string&, const std::vector<double>&, const std::vector<double>&, const std::vector<double>&); void PlotTempFile2D(const std::string&, const std::string&); void PlotTempFile3D(const std::string&, const std::string&); void Dot(const std::string& debugString = ".") const; }; #endif
./CppGnuplotInterface/gnuplotinterface.cpp
//--------------------------------------------------------------------------- // // Gnuplot - a C++ class interface with Gnuplot // V4.0 // // Created by Richel Bilderbeek on Fri Jun 10 2005. // Open source. // // Richel Bilderbeek // Website: http://www.richelbilderbeek.nl // // V4.0: 19th March 2008: Conformized code // V3.0: 23th September 2006: Implemented suggestion by Christoph Schmalz. // According to Christoph it should work under Windows now. // Made the code 100% Standard C++. // V2.0: 12th September 2005: Got program to compile under Windows environment. // Program is found NOT to run under Windows. // Somebody has an idea how to open Gnuplot.exe ??? // V1.0: 10th June 2005: first version developed on Macintosh // // // This class functions well at a Macintosh. Under Windows, the pipe to the // Gnuplot executable (either MS-DOS or Windows executable) will not open. // If you have an idea to solve this, please E-mail me. // // // Feel free to contact me when: // - YOU can get the program to run under Windows (and normally it wouldn't) // - you encounter a compile error // - you have made additional functionality // - you have outsmarted me on this interface. // //---------------------------------------------------------------------------------- #include "UnitGnuplotInterface.h" //---------------------------------------------------------------------------------- //#define EXTENSIVE_LOG //---------------------------------------------------------------------------------- int Gnuplot::mTempFileNumber = 0; //---------------------------------------------------------------------------------- Gnuplot::Gnuplot() : mGnuPipe(0), mTerminal("aqua"), mStyle("lines"), mCurrentWindowNumber(0) { const std::string fileName = ReadFileName(); if (FileExists(fileName)==false) { std::cout << "\nGnuplot file '" << fileName << "' does not exist." << "\nTherefore, change the line in 'GnuplotLocation.txt" << "\nto your Gnuplot location (e.g. 'c:/gnuplot/gnuplot')" << "\nThis error is generated in line " << __LINE__ << "\nof file " << __FILE__ << std::endl << "\n\nPress key to terminate program." << std::endl; std::cin.get(); std::exit(1); } std::cout << "Gnuplot executable found at '" << fileName << "'." << "\nOpening pipe to Gnuplot" << std::endl; mGnuPipe = std::_popen((fileName+" -persist").c_str(),"w"); //Changed 'rw' to 'w' if (mGnuPipe==0) { std::cout << "Couldn't open connection to gnuplot" << std::endl; std::cin.get(); std::exit(1); } SetLineStyles(); AddWindow(); ChangeWindow(0); } //---------------------------------------------------------------------------------- ///This reads the location of Gnuplot from the config file called GnuplotLocation.txt ///If it cannot find this file, it is created with a default value const std::string Gnuplot::ReadFileName() const { const std::string fileName = "GnuplotLocation.txt"; std::string returnFileName; if (FileExists(fileName)==true) { std::ifstream file(fileName.c_str()); assert(file.is_open()==true); file >> returnFileName; file.close(); } else { std::ofstream file(fileName.c_str()); assert(file.is_open()==true); returnFileName ="/sw/bin/gnuplot"; file << returnFileName << '\n'; file.close(); } return returnFileName; } //---------------------------------------------------------------------------------- Gnuplot::~Gnuplot() { const int nWindows = mWindowData.size(); for(int i=0; i!=nWindows; ++i) { mCurrentWindowNumber = i; EmptyPlot(); } if (_pclose(mGnuPipe) == -1) assert(!"Problem closing communication to Gnuplot"); } //---------------------------------------------------------------------------------- void Gnuplot::EmptyPlot() { const int nPlots = mWindowData[mCurrentWindowNumber].tempFileName.size(); for (int i=0; i!=nPlots; ++i) { Dot("Removing file: " + mWindowData[mCurrentWindowNumber].tempFileName[i]); std::remove(mWindowData[mCurrentWindowNumber].tempFileName[i].c_str()); } } //---------------------------------------------------------------------------------- void Gnuplot::SetTerminal(const GnuplotTerminal& terminal) { switch(terminal) { case terminalAqua : mTerminal = "aqua"; break; case terminalX11 : mTerminal = "x11" ; break; default: assert(!"Unknown GnuplotTerminal"); } } //---------------------------------------------------------------------------------- void Gnuplot::SetStyle(const GnuplotStyle& style) { switch(style) { case styleLines : mStyle = "lines"; break; case stylePoints : mStyle = "points"; break; case styleLinespoints : mStyle = "linespoints"; break; case styleImpulses : mStyle = "impulses"; break; case styleDots : mStyle = "dots"; break; case styleSteps : mStyle = "steps"; break; case styleErrorbars : mStyle = "errorbars"; break; case styleBoxes : mStyle = "boxes"; break; case styleBoxerrorbars : mStyle = "boxerrorbars"; break; default: assert(!"Unknown GnuplotStyle"); } } //---------------------------------------------------------------------------------- void Gnuplot::Execute(const std::string& cmdstr) const { Dot("Command sent to Gnuplot: " + static_cast<std::string>(cmdstr)); fputs((cmdstr+"\n").c_str(),mGnuPipe); fflush(mGnuPipe); Sleep(1.0); //Setting this sleep time too low results in errors } //---------------------------------------------------------------------------------- void Gnuplot::SetYlabel(const std::string& label) { const std::string command = "set ylabel \""+label+"\""; Execute(command.c_str()); } //---------------------------------------------------------------------------------- void Gnuplot::SetXlabel(const std::string& label) { const std::string command = "set xlabel \""+label+"\""; Execute(command.c_str()); } //---------------------------------------------------------------------------------- ///Change to plotting windows to 'windowNumber'. If this window number is beyond ///the amount of windows created, a new window will be created and that window ///will be set as the plotting window void Gnuplot::ChangeWindow(const int windowNumber) { if (windowNumber==mCurrentWindowNumber) return; if (windowNumber>= static_cast<int>(mWindowData.size())) { AddWindow(); mCurrentWindowNumber = mWindowData.size()-1; } else { mCurrentWindowNumber=windowNumber; } const std::string myCommand = "set terminal "+mTerminal+" "+Itoa(mCurrentWindowNumber+1); Execute(myCommand.c_str()); } //---------------------------------------------------------------------------------- ///Creates an extra 'nWindows' display windows. void Gnuplot::AddWindow(const int nWindows) { for (int i=0; i!=nWindows; ++i) { WindowData temp; mWindowData.push_back(temp); } } //---------------------------------------------------------------------------------- void Gnuplot::Plot(const std::string &equation, const std::string &title) { std::string myCommand; if (mWindowData[mCurrentWindowNumber].tempFileName.size() > 0) myCommand = "replot " + equation + " title \"" + title + "\" with " + mStyle; else myCommand = "plot " + equation + " title \"" + title + "\" with " + mStyle; Execute(myCommand.c_str()); } //---------------------------------------------------------------------------------- void Gnuplot::Plot(const std::vector<double>& x, const std::string &title) { const std::string tempFileName = CreateTempFileName(); CreateTempFile(tempFileName,x); PlotTempFile2D(tempFileName,title); } //---------------------------------------------------------------------------------- void Gnuplot::Plot(const std::vector<double>& x, const std::vector<double>& y, const std::string &title) { const std::string tempFileName = CreateTempFileName(); CreateTempFile(tempFileName,x,y); PlotTempFile2D(tempFileName,title); } //---------------------------------------------------------------------------------- void Gnuplot::Plot(const std::vector<double>& x, const std::vector<double>& y, const std::vector<double>& z, const std::string &title) { const std::string tempFileName = CreateTempFileName(); CreateTempFile(tempFileName,x,y,z); PlotTempFile3D(tempFileName,title); } //---------------------------------------------------------------------------------- void Gnuplot::PlotTempFile2D(const std::string& tempFileName, const std::string& title) { std::string myCommand; const int nSeries = mWindowData[mCurrentWindowNumber].tempFileName.size(); //Linestyles are nice, but don't work on my terminal... ///if (nSeries>12) std::cout << "MAKE MORE LINESTYLES!!!" << std::endl; //if ( nSeries == 0) // myCommand = "plot \"" + tempFileName + "\" ls "+Itoa(nSerie)+" title \"" + title + "\" with " + mStyle; //else // myCommand = "replot \"" + tempFileName + "\" ls "+Itoa(nSerie)+" title \"" + title + "\" with " + mStyle; if ( nSeries == 0) myCommand = "plot \"" + tempFileName + "\" title \"" + title + "\" with " + mStyle; else myCommand = "replot \"" + tempFileName + "\" title \"" + title + "\" with " + mStyle; Execute(myCommand.c_str()); Sleep(1.0); //Setting this sleep time too low results in errors mWindowData[mCurrentWindowNumber].tempFileName.push_back(tempFileName); } //---------------------------------------------------------------------------------- void Gnuplot::PlotTempFile3D(const std::string& tempFileName, const std::string& title) { //Does not work on my computer. Should be something like this... Execute("set pm3d"); std::string myCommand; if (mWindowData[mCurrentWindowNumber].tempFileName.size() == 0) myCommand = "splot \"" + tempFileName + "\" title \"" + title + "\" with pm3d palette"; else myCommand = "replot \"" + tempFileName + "\" title \"" + title + "\" with pm3d palette"; Execute(myCommand.c_str()); Sleep(1.0); //Setting this sleep time too low results in errors mWindowData[mCurrentWindowNumber].tempFileName.push_back(tempFileName); } //---------------------------------------------------------------------------------- const std::string Gnuplot::CreateTempFileName() { ++mTempFileNumber; const std::string tempFileName = "GnuplotTemp"+Itoa(mTempFileNumber); Dot("Created temp file '" + tempFileName); return(tempFileName); } //---------------------------------------------------------------------------------- void Gnuplot::CreateTempFile(const std::string& tempFileName, const std::vector<double>& x) { std::ofstream file(tempFileName.c_str()); assert(file.is_open()==true); const int size = x.size(); for (int i = 0; i != size; i++) file << x[i] << std::endl; file.close(); } //---------------------------------------------------------------------------------- void Gnuplot::CreateTempFile(const std::string& tempFileName, const std::vector<double>& x, const std::vector<double>& y) { assert(x.size()==y.size()); std::ofstream file(tempFileName.c_str()); assert(file.is_open()==true); const int size = x.size(); for (int i = 0; i != size; i++) file << x[i] << " " << y[i] << std::endl; file.close(); } //---------------------------------------------------------------------------------- void Gnuplot::CreateTempFile(const std::string& tempFileName, const std::vector<double>& x, const std::vector<double>& y, const std::vector<double>& z) { assert(x.size()==y.size()); assert(y.size()==z.size()); std::ofstream file(tempFileName.c_str()); assert(file.is_open()==true); const int size = x.size(); for (int i = 0; i != size; i++) file << x[i] << " " << y[i] << " " << z[i] << std::endl; file.close(); } //---------------------------------------------------------------------------------- void Gnuplot::SetLineStyles() { //Does not work on all terminals. Like mine... :-( //Execute("set style line 1 lt pal frac 0.0 lw 2"); //Execute("set style line 2 lt pal frac 0.0 lw 4"); //Execute("set style line 3 lt pal frac 0.2 lw 2"); //Execute("set style line 4 lt pal frac 0.2 lw 4"); //Execute("set style line 5 lt pal frac 0.4 lw 2"); //Execute("set style line 6 lt pal frac 0.4 lw 4"); //Execute("set style line 7 lt pal frac 0.6 lw 2"); //Execute("set style line 8 lt pal frac 0.6 lw 4"); //Execute("set style line 9 lt pal frac 0.8 lw 2"); //Execute("set style line 10 lt pal frac 0.8 lw 4"); //Execute("set style line 11 lt pal frac 1.0 lw 2"); //Execute("set style line 12 lt pal frac 1.0 lw 4"); } //---------------------------------------------------------------------------------- ///Logging when in developmental phase void Gnuplot::Dot(const std::string& debugString) const { #ifdef EXTENSIVE_LOG std::cout << "DOT: " << debugString << std::endl; #endif } //---------------------------------------------------------------------------------- ///Wait for myTime seconds void Gnuplot::Sleep(const double myTime) const { std::clock_t timeStart = std::clock(); std::clock_t timeEnd = std::clock(); while ((std::difftime(timeEnd,timeStart) / CLK_TCK) < myTime) { //Wait... } } //---------------------------------------------------------------------------------- ///Converts an integer to a string const std::string Gnuplot::Itoa(const int number) const { std::ostringstream o; if (!(o << number)) return "ERROR"; return o.str(); } //---------------------------------------------------------------------------------- ///Converts a double to a string const std::string Gnuplot::Ftoa(const double number) const { std::ostringstream o; if (!(o << number)) return "ERROR"; return o.str(); } //---------------------------------------------------------------------------------- ///Checks if a file exists const bool Gnuplot::FileExists(const std::string& fileName) const { std::fstream fin; fin.open(fileName.c_str(),std::ios::in); if( fin.is_open() ) { fin.close(); return true; } fin.close(); return false; } //---------------------------------------------------------------------------------- //---------------------------------------------------------------------------------- //---------------------------------------------------------------------------------- //---------------------------------------------------------------------------------- //---------------------------------------------------------------------------------- //---------------------------------------------------------------------------------- //----------------------------------------------------------------------------------